The visitors are currently seventh in the table, four points behind sixth-placed Villarreal, while Almeria sit 17th, three points clear of the relegation zone in Spain's top flight.
Match preview
Almeria won promotion back to La Liga by finishing first in the Segunda Division last season, and they are bidding to make it back-to-back campaigns at this level for the first time since 2015.
La Union are one of a number of teams involved in a relegation battle at this stage of the campaign, with a total of 30 points from 29 matches leaving them in 17th, just three points clear of 18th-placed Valencia.
Almeria are only two points behind 14th-placed Real Valladolid, though, so the picture could change on a week-to-week basis, with only Elche at the foot of the table being cut adrift.
Rubi's side picked up five points from their three league matches against Cadiz, Celta Vigo and Valencia between March 18 and April 9, but they will enter this game off the back of a 2-1 loss to Atletico Madrid.
UDA have been impressive on home soil this season, picking up 26 points from 15 matches, which is fortunate considering their away form is the worst in the division, only collecting four points from 14 games.
Athletic, meanwhile, are in strong form at the perfect stage of the season, winning three and drawing one of their last four league games to strengthen their hopes of a top-six finish.
The Basque outfit suffered disappointment in the semi-finals of the Copa del Rey, losing 2-1 on aggregate to Osasuna, who will take on Real Madrid in the final, but the response has been impressive, and they will enter this game off the back of successive wins over Espanyol and Real Sociedad.
Last Saturday's 2-0 success over Real Sociedad was earned courtesy of a double from Inaki Williams, and the Lions will now be looking to record their 13th league victory of the campaign on Saturday.
Athletic have not finished higher than seventh in La Liga since the 2015-16 campaign, when they were fifth, so it could be a very strong campaign for the club despite their failure to reach the Copa del Rey final.
Ernesto Valverde's side have picked up 19 points from their 14 away league fixtures this term, while the team have won eight of their last nine top-flight games against Almeria, including a 4-0 victory when the two teams locked horns at San Mames in the reverse match this term.
Almeria La Liga form:
L
L
D
D
W
L
Athletic Bilbao La Liga form:
D
L
W
D
W
W
Athletic Bilbao form (all competitions):
L
W
D
D
W
W
Team News
Almeria will be missing Alejandro Pozo, El Bilal Toure and Sergio Akieme on Saturday through injury, while Largie Ramazani is suspended due to the yellow card that he picked up against Atletico last time out.
Head coach Rubi is expected to keep faith with the majority of the side that took to the field for the first whistle against Diego Simeone's side, with Leo Baptistao supporting Luis Suarez in the final third.
Gonzalo Melero played in an advanced area against Atletico and that is again likely to be the case here, but there could be a change on the right, with Arnau Puigmal potentially coming in for a start.
As for Athletic, Inigo Lekue and Jon Morcillo remain on the sidelines through injury, while Dani Garcia is banned following his red card in the Basque derby last time out.
The visitors will be boosted by the return of Oscar de Marcos, though, with the Spaniard available after serving a suspension against Real Sociedad.
Ander Herrera could come into the XI as Dani Garcia's replacement, but Inaki Williams, Oihan Sancet, Nico Williams and Gorka Guruzeta should continue as the front four on Saturday.
Almeria possible starting lineup:
Martinez; Kaiky, Ely, Babic; Puigmal, Robertone, Costa, Centelles; Melero, Suarez, Baptistao
Athletic Bilbao possible starting lineup:
Simon; De Marcos, Yeray, I Martinez, Yuri; Vesga, Herrera; I Williams, Sancet, N Williams; Guruzeta
We say: Almeria 1-1 Athletic Bilbao
Almeria have picked up as many home points this season as Villarreal, with their hopes of staying in the league likely to depend on their form at home. Athletic are on a roll at the moment, winning three of their last four, but we have a feeling that the points will be shared during a tight contest.